Variable Compression Piston Rod Axial Cooling Flow Path
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Solution Overview
Problem
Existing engine systems face challenges in stably supplying a cooling fluid to the piston and maintaining the movable range of the piston rod due to the variability in the relative position between the piston rod and the fluid chamber, which limits the adjustment mechanism's effectiveness in changing compression ratios.
Innovation Solution
A variable compression device with a piston rod featuring a flange and a regulation member, where the flange forms the bottom surface of a fluid chamber, allowing for a separate supply flow path to guide cooling fluid into the piston rod, eliminating the need for radial flow paths and enhancing the piston rod's movement range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cooling fluid is supplied through an opening formed on the side of the piston rod, then the cooling fluid can be supplied to the inside of the piston, but the movable range of the piston rod is limited due to the need for a large opening
Solution Approach 1:
The supply flow path is configured to supply cooling fluid from the axial direction (top surface of flange) rather than requiring a radial opening on the piston rod side surface. This dimensional change in fluid supply direction eliminates the need for large radial openings, preserving the piston rod's full movable range while ensuring stable cooling fluid supply to the piston interior.
2Adaptability or versatility
If the working fluid leaking out from the hydraulic chamber is used as cooling fluid, then resource utilization is improved, but stable supply of working fluid to the piston is difficult
Solution Approach 1:
The hydraulic chamber and cooling fluid supply system are segmented into separate functional zones. The supply flow path includes a first flow path for hydraulic fluid supply to the hydraulic chamber and a second flow path for cooling fluid supply to the piston, allowing independent control and stable cooling fluid supply while maintaining working fluid utilization efficiency.
3Adaptability or versatility
If the relative position between the piston rod and the fluid chamber varies with compression ratio, then the compression ratio adjustment is achieved, but the opening on the piston rod side must be large to accommodate all positions
Solution Approach 1:
The cooling fluid supply flow path is configured in the axial direction through the flange structure, independent of the radial position variation between piston rod and fluid chamber. This allows the piston rod to move freely for compression ratio adjustment without being constrained by cooling fluid supply requirements, as the axial supply path remains effective throughout the full range of motion.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration ensures stable cooling fluid supply to the piston rod, increasing its movable range and allowing for more flexible compression ratio adjustments without limiting the piston rod's movement, thereby improving engine efficiency.
Implementation Method 1
a fluid chamber R3 that moves the piston rod 6 in a direction in which a compression ratio is increased by pressurized working fluid being supplied thereto
Implementation Method 2
a piston rod internal flow path R8 that includes an opening end on the bottom surface and guides the cooling fluid in the regulation member-side fluid chamber to an inside of the piston rod
Data Source
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AI summary
The variable compression device (A) includes: a piston rod (6) whose end portion is provided with a flange (6c); a fluid chamber (R3) that causes the piston rod to be moved in a direction in which a compression ratio is increased by a pressurized working fluid being supplied thereto; a regulation member (7c) that is provided such that the flange is interposed between the regulation member and the fluid chamber, and regulates movement of the piston rod in the direction in which the compression ratio is increased; a regulation member-side fluid chamber (R7) that is provided between the flange and the regulation member with the flange forming a bottom surface of the regulation member-side fluid chamber; a supply flow path (R6) that supplies a cooling fluid to the regulation member-side fluid chamber; and a piston rod internal flow path (R8) that includes an opening end on the bottom surface and guides the cooling fluid in the regulation member-side fluid chamber to an inside of the piston rod.